Code of Fair Competition for the Clay and Shale Roofing Tile Industry as Approved on April 6, 1934.United States. National Recovery Administration.1934
Report on the Clay Products Industry (except Pottery and Refractories) for Industry Committee No. 24. April 1941 ...United States. Dept. of Labor. Wage and Hour Division.1941
Rule Relating to Industries Processing Clay or Shale in Their Manufacturing OperationsIndiana Bureau of Factory Inspection1952
Amendment No. 2 April 2019 TO Is 13757: 1993 Burnt Clay Fly Ash Building Bricks - Specificationdiya.singh
Dr. Henry Clay Risner. Hearing before the Committee on War Claims, House of Representatives, Seventy-sixth Congress, third session, on H.R. 3716, a bill for the relief of Doctor Henry Clay Risner. April 2, 1940.United States. Congress. House. Committee on War Claims1940EN
Amendment to Code of Fair Competition for the Floor and Wall Clay Tile Manufacturing Industry as Approved on April 28, 1934.United States. National Recovery Administration.1934EN